This invention relates to heating enclosures such as ovens. In particular it pertains to heating sources designed to produce temperature gradients across objects placed within such enclosures. In even greater particularity this invention is designed to produce such gradients by either radiation and/or convection.
Ovens have been used in the past to simulate weathering and ageing problems. Past ovens have been essentially convection ovens controlled by a single temperature location on the item.
Many items that are subject to field conditions have their useful life limited by the unevenness of heating and cooling which produce temperature gradients within the item. Among the many thermal sources effecting an object outdoors are sun, sky, clouds, wind, ground radiation, reflected solar radiation, and so forth. The net effect of these thermal forcing functions are temperature gradients throughout the object.
Furthermore, these gradients are rarely stable since the thermal sources are subject to constant change, the sun angle constantly changes, the wind fluctuates, and so forth. Thus to adequately field test items, simulation ovens have to be capable of providing different heat sources from different angles.